| Abstract Scope |
Silicon-based anodes have the potential to significantly increase the energy density of lithium-ion batteries, but their use is limited by their tendency to expand in volume which leads to poor performance. Silicon oxycarbides (SiOC) offer a solution to this problem, as they experience less volume change with high theoretical capacity. However, the electronic conductivity of most pure SiOC anodes is poor and their volume expansion is still a concern. To address these issues, a high-performance SiOC anode was derived from the mixture of two different polyorganosiloxanes: 1,3,5-Trivinyl-1,1,3,5,5-PentamethylTriSiloxane and 1,3,5,7-tetravinyl-1,3,5,7-tetramethylcyclotetra-siloxane. The resulting SiOC is composed of free carbon phase, SiO4, SiO3C, and SiO2C2 units. This macroporous SiOC anode has a specific capacity of 750 mAh g−1 at 50 mA g-1 demonstrating high Li+ ion reversibility compared to the SiOC derived from individual precursors. The combination of robust multidimensional conductive architecture and chemical composition lead to superior specific capacity and cycling performance. |